利用振动特性诊断流程泵的运行工况

用所建立的用于描述振动强度的范数说明了泵在偏离原设计工况运行时会导致泵轴向力和径向力的增大。将流程泵叶轮叶片和压水室的隔舌看作旋涡发生体，在不同运行工况下在叶片后缘以及隔舌两侧串联发生的卡门涡街的发射频率是不同的。采用加速度传感器采集的振动信号正反应了这种工况变动。通过对振动信号进行基于EMD的能量算子解调以及频谱分析，发现得到的最大幅值处的频率就是叶轮叶片的通过频率。试验表明，得到的次大幅值处的频率就是卡门涡街的发射频率，可根据该频率处幅值的相对大小来判断泵是否在合理的工况内运行。

Diagnosing the running condition of pump by its vibration character

Axial thrust and radial force will increase at off-design condition, which can be explained by a modulus defined specially. The blades of impeller and the tongue of casing are treated as fluid obstacles. The emission frequency of the Karman vortex street occurred in series from the blades and tongue is varing with the running condition. Vibration signals that are acquired by accumulation transducers match with the variation of the conditions. According to the analysis of the vibration signals, the frequency at the point of maximum amplitude is assured to be the passing frequency of blade, and the emission frequency of the Karman vortex street is also abstracted. The running condition is determined finally by the non-dimensional magnitude of the amplitude of the above mentioned emission frequency.